Neuro Flashcards
What drug can be used to confirm a diagnosis of myasthenia gravis?
Edrophonium
ACh esterase Inhibitor
A positive Romberg test indicates a problem in?
Medial lemniscus (dorsal column) - carries proprioception, vibration, light touch Problem with proprioception or vestibular apparatus, sensory deficits
Age related hearing loss is caused by degeneration of?
the proximal hair cells of the organ of Corti
Presbyacusis
harder to hear high pitched voices
A pt with daytime sleepines and decreased sleep time and decreased REM sleep time. Which neurotransmitter is responsible for the decrease in the patient’s REM sleep?
Decreased ACh
ACh induces REM and normal aging is associated with a decrease in ACh.
Older Pt with proximal muscle weakness (difficulty walking up stairs or rising from a chair), delayed relaxation of muscles (slow to unclench a fist), notes that mom had a similar condition
Myotonic dystrophy type 2
nucleotide repeat expansion (CCTG) withing the CNBP gene
Type 1 presents in childhood
What test can be used to confirm a dx of Parkinson?
Clinical response to Dopamine
Microglia are differentiate from which germinal tissue?
Mesoderm. Differentiate from blood monocytes (think of microglia as CNS macrophages)
A pt presents with hoarseness following a thyroidectomy. Which pharyngeal arch is the origin of this nerve?
Branchial arch 6
recurrent laryngeal n. (Branch of X) inn the muscles of the larynx
Following a surgery a pt has difficulty swallowing and absence of gag reflex. Which pharyngeal arch was damaged?
Brnachial arch 4
Superior laryngeal inn paryngeal constrictors, cricothyroid, levator veli palatini
A child presents with a large abdominal mass, HTN, dark circles under the eyes, elevated urine catecholamine. Bx of the mass reveals small round cells with hyperchromatic nuclei forming a pseudorosette pattern around central primative nerve fibers
Neuroblastoma
Most common tumor of the adrenal gland in children
Also most common malignant solid tumor outside of the cranium in children
Caused by amplification of N-myc (protooncogene)
A study that follow subjects without a disease who are then randomized into different levels of exposure to a risk factor and monitored for development of dz is what type of study?
Prospective cohort
Parkinsons dz is caused by degeneration of?
Dopamine producing neurons in the substantia nigra
A pt with a herniated disc at the L5-S1 level will likely have weakness in which reflex?
Compressed S1
Diminished ankle-jerk reflex
A pt with right sided loss of coordination (ataxia), hypotonia, intention tremor, and instability (pt feels like they will fall). Difficulty with finger to nose test on right side. Where is the lesion?
Right cerebellar hemisphere
Cerebellar lesions are ipsilateral
A pt with classic bell palsy where the whole half of his face is paralyzed
Lower moto lesion CN VII
If it was upper motor her would be able to move his eyebrows
During preparation for surgery a pt is confused, tachycardic, tachypneic, and hypertensive. Skin is dry, flushed, warm to the touch with fixed dilated pupils. Pt has been overdosed on?
Atropine
Nonselective muscarining antagonist used in surgery to suppress bronchial secretions
Correct with physostigmine
alpha synuclein deposits is associated with?
Parkinson dz
alpha synuclein = Lewy bodies
A pt presents with uncontrolled DM and diplopia. Right eyelid is drooping and eye is abducted and depressed. Which EOM is still functioning?
Lateral rectus (CN VI) Superior oblique (CN IV) Pt has CN III palsy due to DM neuropathy (inf med and sup rectus, inf oblique)
What is an abortive therapy that is used in a pt with repeat cluster HA?
Oxygen inhalation therapy
Following surgery a pt has lost bilateral motor, pain, and sensation below dermatome T6.
Vibration, light touch, and position sense are intact. What happened?
Hypoperfusion of the anterior spinal a.
Sole vessel that feeds the ventral 2/3 of the spinal cord
artery of adamkiewicz feeds the lower spinal cord (T8-L4)
What is the function of the nodes of Ranvier?
Sites of inward current
Facilitates saltatory conduction
In order to cure Shingles, the drug would have to penetrate the?
Perineurium
This is the tissue that surrounds fascicles of nerve fibers and serves at the permeability barrier in the nervous system
A pt states that his legs violently shakes when he walks and that his dad and uncle had similar symtpoms. On PE the muscles of the leg are held in spasm. Dx and where is the lesion?
Spastic paraplegia AKA hereditary spastic paraplegia
Lesion in the corticospinal tract.
Which tract controls the descending voluntary movements of contralateral limbs?
Lateral corticospinal tract
Legs are Lateral
Symptoms of pancoast/superior pulmonary sulcus tumor
Usually due to non small cell lung cancer in the lung apex
ipsilateral shoulder pain
Horner syndrome (ipsi)
Atrophy of intrinsic hand m. (ipsi)
Upper extremity edema (vascular compression)
DO NOT present with classic lung cancer syx
A neonate presents with a tuft of hair on her back covering a dimple over L5. No neuro defect
Spina bifida occulta
Spina bifida cystica would incl. the meninges and sometimes the spinal cord
The patellar reflex tests which nerves?
L3 and L4
A pt presents with weakness in her left leg ONLY. Occlusion is likely in the?
Right anterior cerebral a.
A pt with organophosphate poisoning should be treated with?
Pralidoxime
Organophosphates are acetylcholinesterase inhibitors and can become irreversible if they aren’t treated quickly. Excessive cholinergic stimulation = DUMBBELSS (Diarrhea, urination, miosis, bronchospasm, bradycardia, excitation of skeletal muscle and CNS, Lacrimation, sweating, salivation)
FGFR is a defect in the maturation of which tissue?
Cartilage
Achondroplasia
AD
A pt that recently started an antipsychotic for suicide attempts is presenting with a head tilt that cannot be straightened without considerable pain. Dx?
Acute dystonic reaction (spasmodic torticollis) due to Dopamine antagonism in the migrostriatal pathway
Extrapyramidal symptom of antipsychotic medications
Action of benzodiazepines
Increase frequency of Cl- channel opening
Action of barbituates
Increase duration of Cl- channel opening
A pt that carries the apolipoprotein E-4 allele is at risk for?
Late onset Alzheimer dementia
What are the genetic risk factors for early onset (
- Amyloid precursor protein (APP on chr 21)
- Presenilin 1 on chr 14
- Presenilin 2 on chr 1
Pentapeptides with affinity for delta and mu receptors
Enkephalins, endorphins, and dynorphins = endogenous opioid peptides
Release in response to pain for pain modulation
Which molecules are made from the precursor polypeptide proopiomelanocortin (POMC)
Beta-endorphins (endogenous opioid peptide)
ACTH
MSH
A 2 day old is presenting with tremors, tachypnea, sneezing, diarrhea. Mom has poorly controlled schizophrenia, Hep C, and received limited prenatal care. Baby has increased tone and quiets when swaddled. Dx?
Neonatal abstinence syndrome due to opiate w/d
Tx - methadone or morphine. Increase dose until syx resolve and then taper the baby off over several weeks
Would you give naloxone to a pt in opiate w/d?
No. This is a pure opiod receptor antagonist and would worsen w/d symptoms. Only use in overdose. Use methadone for w/d
Why do you give a pt cabidopa and levodopa?
Carbidopa inhibits peripheral conversion of levodopa making it more available to the brain
What behavioral changes can be seen in high dose combo of levodopa and carbidopa?
anxiety, agitation, insomnia, confusion, delusions, hallucination
Can try reducing dose or adding an antipsychotic (clozapine)
A neonate is born with underdeveloped mandible and hypoplastic zygomatic bones due to failure of development of the first and second pharyngeal arches. What other structure is probably abn?
Stapes
Treacher-Collins syndrome = genetic disorder causing abn development of first and second pharyngeal arches
Craniofacial abn lead to ariway compromise, feeding difficulties, conductive hearing loss
A pt injured his shoulder and presents with sensory loss over the lateral shoulder and weakness on should abduction
Axillary n. injury
Weakness due to denervation of the deltoid
Pt has shooting pain down the back of her leg. + straight leg test, weak hip extension. Absent ankle jerk reflex. Dx?
Sciatica (L4-S3)
Usually caused by disc herniation
Prenatal valproate use (bipolar, epilepsy) increases the risk of the fetus developing?
Nueral tube defecs
What do inhalation anesthetics, barbiturates and benzos target in order to achieve CNS depression?
Potentiate the inhibitory action of GABA
Other than the desirable CNS effects, what other affects do inhaled anesthetics have on the body?
- Decreased CO (hypotension)
- Respiratory depression (hypercapnia)
- Decreased vascular resistance in the brain (increased cerebral blood flow)
- Decrease GFR
- Decreased hepatic flow
What is the most likely sequelae of untreated congenital hydrocephalus?
Muscle hypertonicity
Congenital hydrocephalus is usually caused by?
Malformation that prevents drainage of CSF (Chiari, Dandy-Walker, infection, hemorrhage
Teenage boy presents with intellectual disability/ADHD, prominent forehead, long and narrow face, prominent mandible, large testes, hyperlaxity of finger and thumb joints
Fragile X syndrome
loss of function mutation in fragile X mental retardation 1 gene (FMR1)
A pt has bilateral visual difficulty that is progressing. Fundoscopy reveals small yellow retinal lesions clustered in the macula. What would you expect on visual field exam?
Central scotomas
scotoma = any visual defect surrounded by a relatively unimpaired field of vision
Dx = Macular degeneration
What is the pathogenesis of macular degeneration?
progressive loss of central vision due to deposition of fatty tissue (drusen) behind the retina (dry MD) and neovascularization of the retina (wet MD)
A pt with a fx on the orbital floor (zygomatic and maxilla) is likely to have injury to which nerve?
Infraorbital n.
May have loss of sensation over the upper lip
A child presents with difficulty walking, frequent respiratory infections, cerebellar atrophy and impaired DNA repair. Dx?
Ataxia - telangiectasia
ar
DNA is hypersensitive to ionizing radiation and increases risk of cancer
Blood solubility of an anesthetic is indicated by its
Blood/gas partition coefficient
High solubility has a higher partition coefficient
A drug that has higher solubility will have a slower rise in partial pressure in the blood, but it will be able to unload in the brain faster.
A pt with contralateral homonymous hemianopia with macular sparing (ie blind in the right half of each visual field) has a occlusion in?
Posterior cerebral a.
Macula is spared due to collateral blood from the middle cerebral a. to the occipital pole
An MS patient will experience a decrease in which neuronal property as a direct result of demylination?
Length constant
AKA space constant
measures how far along an axon a signal can propogate
How do you treat a pt with status epilepticus?
- Lorazepam (benzo) to abort active seizure
- Phenytoin (blocks inward movement of Na+) - for long term management
If seizure continues - give a barb
Pt presents with Left arm clumsiness. On PE - motor weakness of left arm and leg, slurring, drooping of left lower face. Passive extension has initial resistance followed by sudden release of tension (clasp-knife spasticity). Where is the lesion?
Internal capsule
Clasp-knife spasticity suggests UMN lesion due to lack of inhibition. Can affect any portion of pyramidal motor system.
Internal capsule stroke = pure motor weakness affecting contralateral arm, leg, lower face
A pt wants a sleeping pill that isn’t addictive. You recommend
Zolpidem
short acting hypnotic that is unrelated to benzo’s but action is similar (enhance GABA). Short term treatment of insomnia
Eye adduction depends on which nerve?
Occulomotor (CNIII)
A pt with Down’s syndrome that is become increasingly forgetful likely has?
early onset Alzheive
~ 40 y/o
Increased neuronal amyloid precursor protein
Pain sensation from the median sulcus of the tongue anterior to the foramen cecum is carried by?
Mandibular division of trigeminal n. (ant 2/3 of tongue)
Posterior 1/3 of tongue has sensory inn by?
glossopharyngeal (CN IX)
Anterior 2/3 of taste buds are inn by?
Chorda tympani of facial n. (CNVII)
Posterior 1/3 of taste buds are inn by?
Glossopharyngeal n (CN IX)
At autopsy a pt has an atrophic precentral gyrus and thin anterior roots of the spinal cord. On microscopy loss of neurons in the anterior horn of the spinal cord and in the hypoglossal and ambiguous CN nuclei. Corticospinal tracts stain only lightly (demyelinization) dx?
Amyotrophic lateral sclerosis
Combined UMN and LMN lesions
A pt with a pure motor hemiparesis (ie right sided weakness) and a small cavitary lesion in the internal capsule likely has a ?
Lacunar infarct
Caused by Hypertensive arteriolar sclerosis due to chronic HTN
CT is negative acutely but will show the cavitory lesion after a few weaks
In a pt with absence seizures, treat with?
Ethosuximide
Decreases calcium current in thalamic neurons (blocks T-type Ca2+ channels)
Which seizure medications inhibit neuronal firing by reducing Na+ entry?
Phenytoin
Carbamazepine
Valproic acid
Following an appendectomy a pt loses sensation over the suprapubic area but cremaster reflex is intact. Which n. was damaged?
Illiohypogastric
L1
motor function to anterolateral abdominal wall m.
What determines potency of an inhaled anesthetic?
Minimal alveolar concentration
% of anesthetic in the inspired air that renders 50% of patients unresponsive to painful stimuli
Potency = 1/MAC
Does NOT depend on pt height weight or gender
A pt presents with HA’s caused by an expanding neoplasm in the cerebellar hemisphere. What other finding would you expect in this pt?
ipsilateral
- dysdiadochokinesia (impaired rapidly alternating movements)
- limb dysmetria (over or under shoot during targeted movement)
- Intention tremor
Why do DM pts get peripheral neuropathy?
- Non-enzymatic glycosylation of neuron leads to Endoneural arteriole hyalinization and eventual nerve ischemia
- Intercellular hyperglycemia occurs in peripheral nerves = glucose is converted to sorbitol and fructose. Sorbitol increases osmolarity and facilitates water influx in the cell
A middle aged Caucasian woman is unable to walk. Spinal cord shows symmetric myelin layer vacuolization and axonal degeneration of posterior column and lateral corticospinal tracts
Subacture combined degeneration
Vitamin B 12 deficiency causes abn myelin synthesis. Leads to degeneration of:
1. Dorsal column (bilateral loss of position and vibration sense)
2. Lateral corticospinal tracts (UMN signs)
3. Axonal degeneration of peripheral nerves (numbness, parathesia)
Kid with hypoplasia/absence of cerebellar vermis and cystic dilation of 4th ventricle?
Dandy Walker malformation
Present with developmental delay, skull enlargement, unsteadiness, impaired coordination
Can develop non communicating hydrocephalus
A pt with a solitary mass in right temporal is likely to have which visual field defects?
Left homonymous superior quandratanopia
“Pie in the sky”
Upper Left corner lost in both eyes
NOTE contralateral
Neuritic plaques are found in pts with?
Alzheimer’s dz
Neuritic plaque = neurofibrillary tangle
Aggregates of hyperphosphorylated tau protein
A pt has a bilateral hand tremor that improves when she drinks a small amount of alcohol. Dx and Tx?
Dx - Essential tremor, AD
Tx - Propanolol, non selective beta blocker
A kid with Absence seizures that have be refractory to other antieplieptics is given lamotrigine. What side effect should he be warned of?
Stevens - Johnson syndrome (toxic epidermal necrolysis)
What is the MOA for lamotrigine?
Blocks voltage gated Na channels
Use in partial and generalized seizures. Also effective in bipolar
Which anticonvulsants can cause Stevens-Johnson syndrome?
Lamotrigine Carbamazepine phenobarbital Phenytoin If any rash develops, d/c immediately
Epidural hematoma is caused by rupture of?
Middle meningeal artery
lucid interval
Lens shape
Trauma, skull fx
Subdural hematoma is caused by rupture of?
Briding veins
Gradual headache with a slow decline in mental function
Crescent shape
Elderly pt prone to falls
Pt has a large left lung mass on CXR and presents with shoulder pain, persistant hiccups, dyspnea, decreased breath sounds on L side. Which nerve is being compressed?
Phrenic n. (C3-C5)
inn ipsi hemidiaphragm (decreased breath sounds on L)
Referred shoulder pain = C3
From top to bottom, what is the order of the nerves leaving the brachial plexus?
Musculocutaneous n. Axillary n. Radial n. Median n. Ulnar n.
Damage to the radial n. would result in?
Wrist drop
Unable to extend wrist
Weakness in wrist flexion is due to damage in which nerve?
Median or ulnar
A pt undergoing rotator cuff surgery is given an injection of anesthesia between the right anterior and middle scalene to block the brachial plexus. Which other muscle is likely to be paralyzed?
Diaphragm
Brachial plexus = C5-T1
Phrenic n. = C3-C5
Avoid interscalene block in pts with lung dz or contralateral phrenic n. dysfunction
A pt with diplopia and new hand/foot clumsiness likely has depletion of which cell type?
Oligodendrocytes
Dx = MS
Communicating hydrocephalus is caused by a defect in?
Arachnoid granulations NO obstruction in CSF flow Usually a sequelae of meningitis or hemorrhage All ventricles symmetrically enlarged Wet Wacky Wobly
What is the pathway of CSF flow through the ventricles?
Choroid plexus secretes CSF into lateral and 4th ventricle
Lateral ventricle -> interventricular foramen of Monro -> 3rd ventricle -> Cerebral aqueduct -> 4th ventricle -> foramina of Luschka and Magendie -> subarachnoid space -> absorbed by arachnoid granulations -> venous sinuses
Non communicating hydrocephalus is a defect in?
Normal flow of CSF
Only ventricles above the obstruction will be dilated.
Congenital anomalies - Dandy-Walker, Chiari, aqueductal stenosis
A pt with vision loss on one side likely due to a lesion?
contralateral optic tract
Optic tract comes after the optic chiasm
Will also have a defect in pupillary light reflex in the contralateral eye
Which nerves would be affects in Jugular foramen (Vernet) syndrome?
CN IX, X, XI
IX - loss of taste in post 1/3 of tongue,
IX, X - loss of gag, dysphagia
X - Dysphonia, hoarseness, uvula deviates away from lesion
XI - SCD, trapezius m. paresis
An anesthetic has a very large arteriovenous concentration gradient after beginning inhalation
Slow onset of action
Onset of anesthesia depends on when sufficient quantity of anesthetic is transferred to the brain.
A pt presents with parathesia over their thumb and first two fingers
Carpal tunnel syndrome (CTS)
Compression of median n., often bilateral
Assoc with pregnancy, hypothyroidism, DM, RA, amyloid (decreases carpal tunnel space)
Pt presents with a HA and a right pupil that is dilated and non reactive to light and accomodation, vertical and horizontal diplopia. Right eye is down and out with ipsilateral ptosis. Dx?
CN III exits midbrain between posterior cerebral and superior cerebellar a. - and aneurysm in either artery can cause a non-pupil sparing CNIII palsy
If the pupil was spared, more likely that the syx would be due to ischemia
A pt with stabbing pain in the extremities and stumbling at night tests positive for VDRL. Where is the degeneration in the spinal cord?
Tabes dorsalis (neurosyphilis)
Damage to sensory n. in dorsal roots leading to demyelination and loss of axons in the dorsal column of the spinal cord.
Pain, parathesia, and loss of virbratory and position sense.
Expect Argyll Robertson pupils and + Romberg on PE
Following delivery a woman presents with urinary incontinence and mild preineal pain. DTR or 2+ with normal tone. Cause?
Pudendal n. injury (S2-S4)
Reenters the pelvis near the ischial spine (prone to stretch injury)
Inn pelvic floor, external urethral and anal sphincters
21 year old presents with HA, dizziness, and gait imbalance. HA are over occipital region and MRI reveals low-lying cerebellar tonsils. Dx?
Chiari malformation type I (congenital)
Cerebellar tonsils herniate through foramen magnum
e)
What is unique about Chiari malformation type II?
type I - benign, presents in teen/young adult as HA and dizziness
Type II - neonate, non communicating hydrocephalus (aqueductal stenosis), dysphagia, strido, apnea
50 year old man presents with loss of inhibition, irritability, and personality change. Dx?
Frontotemporal dementia (Pick's dz) Atrophy of frontal and temporal lobes
What are pick bodies made of?
cytoplasmic inclusions of microtubule associated protein tau
Initial syx = personality change (apathy, socially inappropriate behavior)
Teenage girls presents with gait instability. Progressive clumsiness, Kyphoscoliosis, pes cavus, bilateral lower extremity ataxia. Position and vibration sense impaired. Dx?
Friedreich ataxia
ar, lateral corticospinal tract involvement
At risk of developing hypertrophic cardiomyopathy (most common COD)
Which medication induce CYP450?
Phenytoin Rifampin Barbiturates Carbamazepine Griseofulvin Alcohol
Which medications inhibit CYP450?
Isoniazid Cimedtidine Macrolides Azoles Grapefruit juice
A 78 y/o right handed man has a PMH of two TIA’s and HTN. He is presenting with inability to recognize people visually. What visual disturbance is likely?
Loss of upper left corner in both eyes
Prosopagnosia (inability to recognize faces) suggest right inferior temporal lobe, specficially the right fusiform gyrus. This is fed my the middle cerebral a. Presents with crontralateral superior visual field quadrant loss
Contralateral b/c it is behind the optic chiasm
What CT findings may be seen in a pt with Myasthenia gravis?
anterior mediastinal mass due to thymic abnormalities (thymoma, thymic hyperplasia)
A child with a history of untreated absence seizures presents with a tonic-clonic seizure. Tx?
Valproate
Both ethsuximide and valproate can be used in absence seizures, but valproate is prefererd in pts with combined absence and tonic-clonic seizures
MOA of ethosuximide?
blocks T-type Ca2+ channels that trigger and sustain rhythmic pulsed discharges in thalamic neurons
An elderly pt presents with vision problems and right-sided hemisensory loss x 1 hr. On CT multiple small lobar hemorrhages of varying ages in the occipital and parietal areas with a medium-sized acute bleed in the left parietoccipital lobe. Similar findings have happened before. Dx?
Cerebral amyloid angiopathy
Most common cause of spontaneous lobar hemorrhage especially in the elderly. Usually in the occipital or parietal lobes
Consequence of Beta amyloid deposition in the walls of small to medium sized a. Same proteins as Alzheimer dz
occipital hemorrhage = homonymous hemianopsia
Parietal hemorrhages = contralateral hemisensory loss
What nerve is involved in temporomandibular disorder?
Mandibular branch of CNV
Supplies inn to the middle ear and muscles of mastication
35 y/o mechanic presents with progressive hand weakness. Sensation is preserved in upper limbs but weakness of extension of fingers and thumb. Strength intact and reflexes 2+ and symmetric. The affected nerve is most likely injured at which location?
Supinator Canal
Radial n.
As it passes through the supinator canal may have damage due to repititive pronation/supination of the forearm (tools), direct trauma, or subluxation of the radius. Presents with weakness of extension (“finger drop”) without wrist drop or sensory deficits
Pt presents with impaired vision, rapidly progressive dementia, and myoclonic jerks. Slips into a coma and dies 6 mo later. Dx?
Creutzfeld-Jakob dz
Rapidly progressive dementia and myoclonic jerks, multiple vacuoules in the gray matter (spongiform encephalopathy)
Prion dz
Smoker presents with R shoulder and arm pain x 2 months. He has right sided ptosis with fully intact EOM. Asymmetric in dim light but both equally reactive in full light. Right upper extremity is 3/5 on strength and absent DTR’s. Whats going on??
Dysfunction in the autonomic ganglia
Pancoast tumor
Ipsilateral shoulder pain, upper limb parathesia, areflexic arm weakness (Brachial plexus)
Horner syndrome due to cervical sympathetic ganglia involvement
Pt is diagnosed with a cavernous hemangioma. At risk of developing?
Intracranial hemorrhage and seizures
Cavernous hemangioma = vascular malformation in the brain parenchyma.
Appear as an irregular hyperdense/bright mass on CT
A pt with arm parathesia develops a right sided convulsion followed by a general tonic-clonic seizure. Where is the origin of the seizure?
Contralateral sensory cortex
A partial (focal) seizure arising in this region would cause contralateral sensory disturbance (numbness, parathesia)
Stroke is the most common cause of seizure, look for a pt with recent d/c of anticoagulant
It did spread to both hemispheres causing the general tonic-clonic seizure
A pt on phenytoin x 6 weeks is presenting with fever and skin rash involving 60% of her body. What lab findings would be expected?
Eosinophilia
Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrom occurs 2-8 weeks after starting high risk drugs: anticonvulsants (pheny, carbamazepine), allopurinol, sulfonamides, abx (vanco)
Fever, general lymphadenopathy, facial edema, diffuse rash, eosinophilia, internal organ dysfunction
Rare, potentially life threatening
A drug is given to a pregnant dog and it causes decreased uterine contractions and dilates the pupil. Which adrenergic activity does this drug have?
Alpha and beta agonist
alpha 1 = pupil dilation (mydriasis)
beta 2 = uterine smooth muscle relaxation (tocolysis)
A pt with myasthenia gravis is still symptomatic despite receiving low dose pyridostigmine. He has significant improvement following edrophonium infusion. What should be done?
Increase pyridostigmine dosage (AChE inhibitor)
Clinical improvement following edrophonium suggests the pt is undertreated (myasthenic crisis)
Cholinergic crisis would be due to excessive ACh in the synapse and syx would worsen with edrophonium (d/c AChEI)
Following a biopsy in the posterior cervical triangle a pt says he has difficulty with overhead activities. PE - L shoulder droop, weak arm abduction. No sensory loss. Which m. is paralyzed?
Trapezius m.
Spinal accessory n. (CNXI, pure motor) was injured during bx.
Drooping shoulder, impaired abduction of the arm above horizontal (weakness in rotating the glenoid upward), winging of the scapula
20 y/o woman reports frequently burning herself because she can’t sense temperature. PE - decreased pinprick and temperature sense in the upper extremeties. Dx and where is her spinal cord damaged?
Syringomeylia
Damage to ventral white commissure in the cervical region
Bilateral loss of pain and temp sensation limited to the arms and hands.
Destruction of motor neurons in the ventral horns (due to extension of the syrinx) causes flaccid paralysis and atrophy of the intrinsic m. of the hand
What is a syrinx filled with?
CSF, can enlarge over time
What does the central white commissure of the spinal cord do?
It is the site of decussation of the lateral spinathalamic tract (pain, temp) from the periphery to the somatosensory cortex
thats why you get BIlateral loss of pain and temp
1st order = dorsal root ganglia
2 = decussate in the ventral white commisure and asced in contralateral lateral funiculus
3rd = VPN of thalamus
4th = primary sensory cortex of parietal
a baseball pitcher presents with right arm weakness and numbness. PE - diminished strength on elbow flexion and absent biceps reflex. What sensory loss would be expected?
Lateral forearm
Musculocutaneous n. (C5-C7, lateral cord) damage inn the major arm flexors (biceps, brachialis) and caracobracialias (flex and adduct arm.
Sensory to lateral forearm
4 y/o presents with morning emesis x 2 weeks and painful HA when lying down. Intermittent blurry vision especially when looking up. PE - bilateral papilledema, inability to look up, bilateral eyelid retraction. Where is the mass?
Pineal gland
Germinoma is most common.
Presents with obstructive hydrocephalus and doral midbrain syndrome (Parinaud).
Germinomas in the suprsellar region cause endocrinopathies due to pituitary/hypothalamic dysfunction
What is Parinaud syndrome?
limitation of upward gaze with a downward gaze preference, bilateral eyelid retraction, and light-near dissociation (pupil accommodate but do not react to light)
Bx of a intracranial mass in a 33 y/o is composed of elongated cells with regular oval nuclei. Biphasic pattern of growth with areas of dense cellularity interspersed with less dense myxoid regions. S-100 + Dx?
Schwannoma Biphasic pattern of cellularity S-100 + (neural crest origin) Peripheral n., n. roots, and cranial n. Acoustic neuroma is most common at the cerebellopontine angle (CN VIII)
What two tumors are S-100+?
Schwannoma
Melanoma
Because both are derived from neural crest cells
Does MS syx worsen with heat exposure, or cold exposure?
Heat exposure. Showers, exercise
What type of necrosis affects the brain?
Liquefactive
Complete digestion of necrotic tissue with formation of a cystic cavity. Also see this with bacterial or fungal infection
Lysosomal digestion of tissue
gliosis = scar formation
MOA of selegiline?
MAO type B inhibitor
Parkinson Dz
Many neurologists like to use selegiline, anticholinergics, and amantadine until they can no longer control the syx. Then they will switch to levodopa/carbidopa
MOA of amantadine?
Antiviral with dopaminergic activity. Used in parkinsons
Homeless man presents with elevated amylase/lipase and develops confusion during his hospitalization. Imaging demonstrates bilateral lesions in the mamillary bodies and the periaqueductal gray matter. What caused this?
Glucose infusion
glucose infusion without thiamine supplementation in a pt with chronic thiamine deficiency causes encephalopathy.
Wernicke enceph = confusion, ataxia, ophthalmoplegia
Mamillary body hemorrhage
HIV pt presents with personality changes. MRI shows a single mass in the temporal lobe and bx reveals EBV infected cells. Dx?
Primary CNS lymphoma
Most common CNS tumor in the immunosuppresed. Arise from B cells and associated with EBV. High grade tumor with poor prognosis.
Dense cellular aggregates of uniform atypical lymphoid cells.
Diffuse large cell B lymphoma is the most common subtype. CD20/79a +
which is most lateral, the putamen or globus pallidus?
Putamen. Globus pallidus is medial to the putamen but lateral to the internal capsule
Wilson’s dz affects which part of the CNS?
cystic degeneration of the putamen but can affect other basal ganglia structures.
Putamen = medial to the insula and lateral the globus pallidus on coronal sections
21 y/o male presents with impaired balance, tremor, and difficulty speaking slowly progressive x months. Elevated serum transaminases. Cousin has a progressive neuro dz. What diagnostic workup should be ordered?
Slit lamp exam
Wilson dz is ar with excessive copper deposition in the tissues (liver, basal ganglia, cornea)
Young adult with liver dz, neuropsych syx (gait disturbance, dysarthia, depression, personality change), and kayser-Fleischer rings on slit lamp
Where is the caudate?
Inferolateral wall of the lateral ventricle. Internal capsule is lateral to the caudate
What is most important in dx’ing a pt with tetanus?
History and PE
Penatrating wound in an unvaccinated pt
Pt presents with inability to evert foot, numbness over the dorsum of the foot and lateral shin. When walking, he picks the affected foot up high and slaps it to the ground. Dx?
Common peroneal n. injury
Usually caused by trauma near the head of the fibula.
Foot drop and characteristic steppage gait
Pt presents with loss of upper extremity pain and temp sensation, upper extrem LMN signs, and/or lower extremity upper motor neuron signs in the setting of scoliosis?
Syringomyelia
Usually around C8-T1
Scoliosis can occur due to paresis of paravertebral m.
HIV pt x 7yrs presents with cognitive decline (worsening memory, HA, slurred speech, muscle weakness, changes in vision). Dies 2 weeks later of respiratory failure due to pneumonia. What would be seen on brain bx?
Microglial nodules, groups of activated macrophages/microglia around small areas of necrosis. Caused by inflammatory activation of microglial cells
HIV-associated dementia
CD4
How do you get an ischemic vs hemorrhagic stroke?
Ischemic = thrombi, rupture of atherosclerotic plaque. Keeps clotting so can't reperfuse Hemorrhagic = emboli (a fib) can destroy the clot and reperfussion can hemorrhage
A pt with persistent food seeking behavior and a BMI of 32 has a lesion where?
Ventromedial nucleus of the hypothalamus
Satiety center, mediates blood glucose
Fxn of the the lateral nucleus of the hypothalamus?
Mediates hunger
lesion = anorexia
Fxn of the anterior nucleus of the hypothalamus?
Mediates cooling (AC) Lesion = hyperthermia
Fxn of the posterior nucleus of the hypothalamus?
Mediates heat conservation
Lesion = hypothermia
Fxn of the arcuate nucleus of the hypothalamus?
Secretes DA (inhibits prolactin), GHrH, GNRH
Fxn of the paraventricular nucleus of the hypothalamus?
ADH, CRH, oxytocin, TRH (thyrotropin-releasing hormone)
Fxn of the supraoptic nucleus of the hypothalamus?
Secretion of ADH and oxytocin (yea, a little repetitive of paraventricular)
Fxn of the suprachismatic nucleus of the hypothalamus?
Circadian rhythm and pineal gland fxn
Key fx of the hypothalamus?
Maintain homeostasis
Diencephalon
An MS pt is having an exacerbation of painful spasms and stiffness in her legs. What tx would help her?
Baclofen
GABA-B agonist
Effective monotherapy for spasticity secondary to brain and spinal cord dz
Tizanidine is also used
32 y/o male presents with weakness and tingling starting in his feet and now at his knees. Worsens daily. Strength 2/5 bilaterally and absent DTR in the legs. URI about 2 wks ago. Dx?
Guillain-Barre syndrome
Endoneural inflammatory infiltration
Acute demyelinating peripheral neuropathy seen in young adults usually preceded by a febrile illness. Also segmental demyelnation of peripheral n.
Ascending paralysis, Campy infection, immune-mediated with ab cross reacting with myelin
When would you see endoneurial arteriole hyalinization?
DM
A pt with a neoplastic post mandibular parotid mass is likely to develop?
Facial droop
CNVII exits the stylomastoid foramen and courses through the parotid. Malignant tumors will often compress the facial n. causing ipsilateral facial droop
What is strabismus?
Improper alignment of the eyes. Can result from disorders of the EOM or their nerves
A 1 month old is brought to the ED due to somnelence after rolling off a bed. PE - lethargic boy with large, full anterior fontanelle. Bilateral retinal hemorrhages on fundoscopy. Dx?
Abusive head trauma
Shaking baby = subdural hemorrhage (tearing of bridging v.) and retinal hemorrhages (rupture of retinal v.), and posterior rib fx. also hx inconsistent with age. 1 mo old can’t roll (4 mo).
On CT - acute on chronic subdural hematomas
A 42 y/o is brought to the ED due to aggressive behavior. Wife also reports involuntary facial grimaces. Father died from a neuro disorder at age 55. Where is the neuronal damage?
Nucleus caudate, putamen (moderate, less than caudate)
Huntington dz
Progressive dementia, choreiform movement, and behavioral abnormalities
35-45, AD, 100% penetrance
Decreased GABA, ACh, substance P in the striatum (caudate + putamen)
Brain bx demonstrates hippocampus with red deposits on Congo red staining that turn yellow-green under polarized light. Dx?
Alzheimer dz
Amyloid precursor protein accumulation
Chr 21
apple green birefringence due to beta sheet structure
Morphology of liquefactive necrosis
Necrotic cells are completely digested by hydrolytic enzymes forming a viscous liquid mass. Fluid is often creamy yellow due to dead leukocytes (pus). Associated with abscess formation in the peripheral tissues, brain infarcts eventually resolve into CSF filled spaces
In CNS eventually replaced with a cystic astroglial scar
12 y/o presents with chronic HA and visual changes. Imaging reveals an intracranial calcified mass detected on brain imaging. After resection mass shows cystic spaces filled with thick brownish-yellow fluid rich in cholesterol. Mass is most likely derived from cells responsible for forming the?
Anterior Pituitary
Craniopharyngiomas = suprasellar tumors in kids composed of calcified cysts containing cholesterol crystals. Arise from remnants of Rathke’s pouch, an embryonic precursory of the AP.
Rathke’s pouch is an evagination of?
Surface ectoderm that overlies the fetal oral cavity. forms the Anterior pituitary
Where does the posterior pituitary come from?
Neurohypophysis
Forms from an outpouching of the diencephalon (infudibulum) and is derived from neuroectoderm
A pt presents with diplopia and is unable to coordinate their eyes toward the left together. Where is the lesion?
Right dorsal paramedian pons
Internuclear ophthalmoplegia
Disorder of conjugate horizontal gaze in which the affected eye (ispi to the lesion) is unable to adduct and the contralateral eye abducts with nystagmus. Covergence and light reflex are preserved.
Occurs with damage to the medial longitudinal fasciculus
Elderly pt presents with gait disturbance, forgetfulness, urge incontinence. Dilated ventricles on CT. Dx?
Normal pressure hydrocephaly
Caused by decreased CSF resorption by arachnoid granulations.
Triad = wacky, wobbly, wet.
Ventricular enlargement on imaging
Loss of bicep reflex suggests damage of what nerve?
C5-C6
Biceps and brachioradialis reflexes
Pt presents with Right sided weakness and slurred speech, HA, nausea. 240/120 104/min.
PE - lethargic, right flaccid hemiplegia, lower facial weakness, right hemisensory loss, dysarthria. Midline shift on CT. Where is the bleed?
Lenticulostriate arteries
Spontaneous deep intracerebral hemorrhage is usually caused by hypertensive vasculopathy involving the penetrating branches of the major cerebral arteries.
Most frequently affects the basal ganglia (putamen), cerebellar nuclei, thalamus, and pons.
Basal ganglia are supplied by the lenticulostriate a. which a small vessel branches of the MCA
A pt presents with right nasal hemianopia. Where is the defect?
Right peri-chiasmal lesion
Caused by calcification or aneurysm of the ICA impinging on uncrossed, lateral retinal fibers (doesn’t go through the chiasm)
Ipsilateral nasal hemianopia by damagin uncrossed optic nerve fibers from the temporal portion of the retina
A wernicke-korsakoff pt is infused with thiamine. Which neurologic finding is likely to persist despite treatment?
Memory loss
Thiamine should be administered immediately in all pts with wernicke encephalopathy
21 y/o male presents with weakness and gait disturbance. He has been struggling to release the doorknob lately. PE - cataracts frontal baldness gonadal atrophy
Bx - atrophy of type 1 fibers
Dx?
Myotonic dystrophy
AD, increased trinucleotide repeats on myotonia-protein kinase gene. Myotonia with weakness and atrophy is common. Cataracts in nearly all pts and frontal balding and gonadal atrophy are also common
4 y/o has a seizure and presents with a 106 fever. What should be done?
Give Acetaminophen
Antipyretics can improve pt comfort during fever but will not prevent a future febrile seizure
Huntington is caused by a loss of?
GABA containing neurons in the striatum
When a pt presents with chronic hyponatremia, what should you be careful of while treating them?
Too rapid correction leads to demylination of the axons in the central part of the pons (central pontine myelinolysis). Manifests with spastic quadriplegia and pseduobulbar palsy
Contralateral hemiplegia of the face and upper limb with preservation of the lower limb suggests occlusion in the?
Middle cerebral a.
If the dominant hemisphere is occluded (contralateral from handedness) aphasia may occur
Contralateral motor and sensory deficits of the lower extremities, behavioral changes, and urinary incontinence. Where is the occlusion?
Anterior cerebral arteries
Supplies the medial portions of the 2 hemispheres (frontal and parietal lobes)
An animal model develops a T cell response to protein fragments derived from peripheral n. myelin and the animals develop segmental demyelinization of peripheral nerves. What disease is this similar to?
Guillain-Barre syndrome
Immune-mediated acute demyelination of the peripheral nerves. Usually preceded by a febrile illness
Associated with Campy infection
Syx = muscle weakness and areflexia
Severe, episodic, unilateral periorbital and temporal pain associated with lacrimation, nasal congestion, and ptosis
Cluster headache
Usually occurs around the same time each day. More common in males
If anterior horn cells demonstrate cell body rounding, peripheral displacement of the nuclei and dispersion of Nissl substance to the periphery of the cells. This suggests?
Axonal reaction
Changes in the body of the neuron after the axon has been severed. Reflects an increased protein synthesis that facilitates axon repair.
Enlarged, rounded cells with peripherally located nuclei and dispersed finely granular Nissl substance are seen
Neuronal cell demonstrates shrinkage of the neuronal body, deep eosinophilia of the cytoplasm, pyknosis of the nucleus and loss of Nissl substance. This suggests?
Irreversible neuronal injury
Hypoxia, ischemia, or toxic injury
MRI reveals an angiomatous lesion of the cerebellum and a cystic mass int he right kidney. Dx?
Von Hippel-Lindau
AD
Congenital cysts of the kidneys, live and/or pancreas
CNA hamartoma with cyst in the kidney, liver, and/or pancreas
Tuberous sclerosis
Cortical and subependymal hamartomas.
AD
Cutaneous angiofibromas, visceral cysts, variety of other hamartomas
Renal angiomyolipomas and cardiac rhabdomyomas
Seizures is a major complication
On CT a pt has an acute hemorrhage in the left temporal lobe and compression of the anterior medial temporal lobe against the free margin of the tentorium cerebelli. Which nerve is most likely to be compromised?
Oculomotor n.
Transtentorial (uncal) herniation
Complication of an ipsilateral mass lesion, such as a hemorrhage or brain tumor. First sign is a fixed and dilated pupil on the side of the lesion. Ipsilateral paralysis of oculomotor muscles, contralateral or ipsilateral hemiparesis, and contralateral homonymous hemianopsia with macular sparing may also occur
On autopsy a bt has bilateral wedge-shaped strops of necrosis seen over the cerebral convexity, parallel to and a few centimeters lateral to the longitudinal cerebral fissure. What caused this?
Hypoxic-ischemic encephalopathy
Cerebral hypoperfusion may lead to global cerebral ischemia. Watershed infarcts occur between the zones of perfusion of the anterior, middle, and posterior cerebral arteries. Infarcts typically appear as bilateral wedge-shaped strips of necrosis over the cerebral convexity, parallel and adjacent to the longitudinal cerebral fissure
Tetanus causes decreased release of which NT?
Glycine and GABA
Pt has bilateral leg stiffness and involuntary movements. Elevated arginine in plasma and CSF. Where is the deficiency?
Urea cycle, arginase (breaks arginine into urea and ornithine)
Tx - Arg free low protein diet
Why would you decrease the PaCO2 level in a coma pt with diffuse cerebral edema?
To increase cerebral vascular resistance
CO2 is a potent vasodilator in the cerebral vasculature
Decreasing CO2 -> cerebral vasoconstriction -> reduce intracranial pressure
Long narrow face, prominent chin and forehead, large testes
Hyperlaxity of joints in the hand
Developmental delay with overlaping anxiety disorders (autism, ADHD)
Fragile-X syndrome
S-linked
What neuro findings are likely in a pt with ataxia-telangiectasia?
Cerebellar atrophy
Ataxia in first years of life
Repeat sinopulmonary infections
The release of pre-synaptic vesicles from nerve terminals is dependent on?
Calcium influx
Muscarine is a toxin found in certain mushrooms, will act as a?
Muscarinic agonist (ie vasodilation, increased GI motility, increased renal activity)
What should be prescribed for long term management of status epilepticus
Status epilepticus = one seizure lasting more than 5 minutes or ocurence of multiple discrete seizures with incomplete recovery of consciousness between episodes.
Acute tx - lorazepam
Long term - phenytoin (Decreases sodium current in cortical neurons)
What effect does St. John’s wort have on CYP450?
Inducer
Prolactinoma is derived from which embryological tissue?
Surface ectoderm
Lactotroph cells of the anterior pituitary
Which motor protein is involved in anterograde transport of vesicles along microtubules?
Kinesin
Dynein - retrograde
Ataxia telangiectasia is an ar disease that is caused by a defect in?
DNA break repair
ATM gene
Acute dystonic reaction following initiation of a antipsychotic is due to antagonism at which receptor?
Dopaminergic D2 in the nigrostriatal pathway
How does N. meningitidis get access to the CNS?
Nasopharynx -> bloodstream -> choroid plexus -> meninges
H. flu will enter the lymphatics to gain access to the meninges
DIT Mnemonic of CYP450 Inhibitors
Crack Amigos Ciprofloxacin Ritanovir Amiodarone Cimitidine Ketoconazole Acute alcohol use Macrolides Isonazid Grapefruit juice Omeprazole Sulfonamides
DIT Mnemonic of CYP450 Inducers
Guinness Coronas and PBRS induce chronic alcoholism Griseofulvan Carbamazapine Phenytoin Barbituates Rifampin St. John's Wart
Histology of a cerebellar lesion demonstrates neurons with eosinophilic cytoplasm and loss of Nissl substance. How old is the lesion?
12-24 hrs
Any older would have:
PMN infiltration 24-72 hr
Macrophage - 3 to 7 days
Tx for Wilson’s dz?
D-penicillamine
Tremor, hepatic dz
Elevated transaminases, low serum ceruloplasmin
Which seizure med is a significant RF for NTD’s?
Valproate (also used in bipolar)
Supplement with periconceptional folate (vit B9)
In addition to blocking histamine receptors, first gen antihistamines (chlopheniramine, diphenhydramine) have anti effects on?
muscarinic (anticholinergic, blurring of vision)
Alpha adrenergic
sertoninergic
What compound would be low in a narcoleptic pt?
Hypocretin-1 (orexin-A)
Hypocretin-2 (orexin B)
There are neuropeptides produced in the lateral hypothalamus that promote wakefulness and inhibit REM.
Narcolepsy with cataplexy usually have undetectable levels of hypocretin-1 in their CSF
Gum hyperplasia is a common side effect of?
Phenytoin
Can be reversible following d/c
Phenytoin increases expression of platelet-derived growth factor (PDGF)
What is the length constant?
How far along an axon an electrical impulse can propogate.
Myelination - increases length constant and decreases time constant (improved axonal conduction speed)
Demyelination thus impairs stimulus transmission
Tetrodotoxin is a paralytic because it inhibits?
Na+ channels
Puffer fish toxin
What is the underlying pathology of Fragile X syndrome?
Increased CGG trinucleotide repeats on the fragile X mental retardation 1 (FMR1) gene on the long arm of X
Causes hypermethylation and inactivation of FMR1
Elevated acetylcholinesterase on an amnio would indicated?
NTD’s (failed fusion)
Occurs during 4th week of fetal development
alpha-fetoprotein (AFP) may also be elevated
Pt has impaired transport of ornithine from the cytosol to the mitochondria. What should she restrict in her diet?
Protein (decrease accumulation of ammonia)
Ornithine transport into the mitochondria = urea formation
Ornithine + carbamoyl phosphate -> citrulline
Raphe nuclei release?
Serotonin
Inhibited by SSRI’s
Pt presents with an ischemic stroke. On brain bx, which cells will stain the darkest for lipids?
Microglia
Phagocytizing fragments of neurons, myelin, and necrotic debris
Which hypothalamic nuclei helps us to adjust to time changes?
Suprachiasmatic - circadian rhythm regulation and pineal gland fxn
NOT Supraoptic - secretes ADH and oxytocin
Does heteroplasmy affect both sexes equally?
Yes, but there can be variability in disease severity due to random distribution of normal and mutated mitochondiral DNA to each egg during mitosis
Tetrahydropterin is a cofactor in the synthesis of?
Tyrosine Dopamine Serotonin Also causes PKU Tx - low Phe diet and BH4 suppplementation
Which medications can cause suprapubic tenderness and decreased urinary flow?
Anticholinergics (Tricylic antidepressnats (amitriptyline))
Use with caution in elderly
Tx with tamsulosin
Decreased sphincter tone and loss of anal wink following birth due to damage to?
Pudendal n.
A neonate has a weak high pitched cry, prominent scalp veins, and tense fontanels. U/S reveals blood in the lateral ventricles. Which structures is the source of the blood?
Germinal matrix
Neonatal intraventricular hemorrhage
associated with prematurity and low birth weigh. Can have long term neurondevelopmental impairement
Where would a schwannoma be located in the brain?
Between the cerebellum and lateral pons
Cerebellopontine angle
Pattern of inheritance for Neurofibromatosis type 1?
AD
Chr 17
Cafe-au-lait spots, multipe neurofibromas, Lisch nodules
Radial n. damage leads to a defect in?
Wrist extension (ie causes wrist drop)
Damage to the median or ulnar n. would lead to?
Weakness in wrist flexion and thumb opposition
Tx for Alzheimers?
Donepezil (cholinesterase inhibitor)
Antioxidants (Vit E)
NMDA receptor antagonist (memantine)
Meningitis pt with positive latex agglutination. Morphology of the organism?
Budding yeast
Cryptococcus
Methods of transcription silencing?
Histone Deacetylation (Bind tightly to DNA) Methylation mutes
While taking diazepam pts should avoid?
First gen H1 receptor blockers (diphenhydramine, chlorpheniramine) due to significant sedation
pt has blurred vision after working in his garden. Also flushed skin and dry oral mucosa. Tx?
Physostigmine (Cholinesterine inhibitor)
pt is having a atropine OD, Alice’s tea party, probably Jimson weed poisoning, antimuscarine efects)
Following a surgery pt has fever and muscle rigidity, stiffness, and cyanotic skin mottling. Dx and tx?
Malignant hypertermia
Dantrolene (decreases clacium release in skeletal m. by blocking the ryanodine receptor)
Pt has compression of the nerve traversing the L5S1 formen. What would be seen in the lower extremity?
L5 radiculopathy due to spinal foraminal stenosis
Loss of sensation over the buttocks, lateral thigh/calf, and dorsum of the foot
Back pain radiating down the leg
Weakness in foot movements
Pt presents with well-articulated but nonsensical speech. Where is the injury?
Wernicke area
Middle cerebral a.
Where is the pineal gland?
Between the midbrain and thalamus (below lateral ventricles)
Pt presents with severe low back pain x 2 weeks. Pain in lower back with flexing of the back and raising the legs. Loss of pin prick over perineum and anal wink. Dx and which nerve root is affected?
Cauda equina
Saddle anesthesia + loss of anocutaneous reflex
Damage to S2-S4 nerve roots
Pt presents with essential tremor that subsides with alcohol use. How should she be tx?
Propanolol, nonselective B antagonist lessens tremor via CNS effects
AD inheritance
Tremor worsens while trying to maintain a posture (ie holding an object)
Down syndrome pt develops Alzheimer’s due to?
Neuronal amyloid precursor protein
Early onset Alzheimers (~35)
Neurofibrillary tangles and amyloid-beta plaques
APP is present on chromosome 21
Pt presents with right hand clumsiness after following on outstretched hand. Difficulty performing fine finger movements. Where is the damage?
Lower trunk of the brachial plexus (Klumpke’s palsy)
C8 - T1 inn the intrinsic m. of the hand via the median and ulnar n.
Pt presents with sudden onset of difficulty walking and loss of sensation over the right half of her body. PE - loss of touch, temperature, vibratory sensation of the right upper and lower extremities. Loss of sensation on R side of face. Strength intact. Where is the damage?
Ventral posterior thalamus
VPL - receives input from spinothalamic tract and dorsal columns)
VPM - receives from the trigeminal pathway
Sends somatosensory projections to the cortex via talamocortical fibers.
Damage to these nuclei -> complete contralateral sensory loss
Spinothalamic tract carries information about?
Pain Temp Touch Immediate decusation VPL
Dorsal column (media leminiscus) carries information about?
Vibration, proprioception
Light touch
Decussates after ascending two levels
VPL
At autopsy, pt’s brain has two small cavities in the deep structure of the brain filled with clear fluid. What is the cause?
Lipohyalinosis with small vessel occlusion (Lacunar infarct)
How does morphine affect the neurons to reduce pain?
Increase K+ efflux out of the cell
Bind mu receptor -> G protein activation of K+ conductance
Increases hyperpolarization of postsynaptic neurons to prevent pain transmission
What factor correlates to morbidity and mortality in N. meningitidis?
Outer membrane lipooligosaccharide
Acts as an endotoxin and high levels are associated with septic shock and death
May also correlated with Water-house Friderichsen syndrome
Deep intraparenchymal hemorrhage is most commonly due to?
Charcot-Bouchard aneurysm rupture
Caused by hypertensive vasculopathy of the small penetrating branches of the cerebral a.
IC hemorrhage affects deep brain structures (basal ganglia (putamen), cerebellar nuclei, thalamus, and pons)
Rupture of saccular aneurysms generally cause?
Subarachnoid hemorrhage
Enkephalins, endorphins, dynorphins are opiod peptides that share a common molecular origin with?
ACTH, MSH
All derived from POMC
Bx of intracranial mass is positive for synaptophysin and negative for glial fibrillary acidic protein. Neoplastic cells oroginate from the same precursor as?
Neurons Synaptophysic in found in the presynaptic vesicles of neurons, neuroendocrine, and neuroectodermal cells Glial origin (astrocytoma, ependymoma, oligodendrogliomas) stain + for GFAP
types of brain tumors in adults?
Supratentorial
MGM studios
Metastasis
Glioblastoma - most common, astrocytoma :( GFAP+
Meningioma - 2nd, arachnoid cells, resectable, psammoma bodies
Schwannoma - 3rd, benign, S100 +, bilateral acoustic in NFT2
Oligodendroglioma - fried egg appearance
VHL
Hemangioblastoma + RCC
typs of brain tumors in kids
Pilocytic astrocytoma - posterior fossa, GFAP +, rosenthal fibers (eos corckscrew)
Medulloblastoma - cerebellum, Homer Wright rossete, compress 4th vent causing non com hydrocephaly
Ependymoma - perivascular pseudo rossette, compress 4th ventricle, non com hydrocephalus
Characteristics of craniopharyngioma
Derived from Rathke’s pouch
Compression of optic chiasm
Supratentorial tumor in kids
Child presents with new onset tonic-clonic convulsions without fulling regaining consciousness between episodes. Tx and MOA?
Benzodiazepine IV
Enhance post-synoptic voltage gated Cl- channels
Pt presents with brief episode of sudden and severe unilateral “electric shock-like” or “stabbing” pain in the CNV2 and CNV3 distribution. Dx and Tx?
Trigeminal neuralgia (tic douloureux)
Carbamazepine
Triggered by CNV stimuli (chewing, teeth brushing, saving, swallowing, hot/cold)
Non conjugate eye movement and tonic clonic seizures in a child suggests?
Neuroblastoma
N-myc
Most common cause of meningitis in adults?
S. pneumo
Neisseria is second
Pt is unable to dorsiflex or evert the right ankle. Sensation is decreased over the dorsum of the foot. Which n. is damaged?
Common peroneal
Baseball pitcher with right arm weakness is likely to damage which n. and presents with which syx?
Musculocutaneous n. (C5-C7) Arm weakness Loss of sensation over lateral forearm Diminished strength on elbow flexion Absent Biceps reflex (C5)
The necrotic area of the brain following ischemic damage is walled off by?
Astrocytes (glial scar)
Oculomotor palsy (ptosis, down and out eye, mydriasis) occurs due to an aneurysm in the?
Ipsilateral Posterior communicating a.
Cavernous hemangioma increases a pts risk of?
Intracerebral hemorrhage
Tx for restless leg syndrome?
Dopamine agonist (ropinirole, pramipexole) Also associated with iron deficiency
MOA of Triptans?
Postysynaptic serotonin receptor stimulation
5-HT1b/1d agonists
Abortive migraine therapy
Migraine prophylaxis = B block, antidepressants, anticonvulsants
CSF findings for HSV meningitis?
Glucose, protein, cell type
Glucose - NL
Protein - Increased
90% lymphocytes
Pt develops peripheral neuropathy secondary to DM due to?
Endoneural arteriole hyalinization -> leads to ischemic nerve damage
Pt with trigem neuralgia is treated with carbamazepine. MOA?
Decreases Na current on multiple levels
Reduces the ability of Na channels to recover from activation
SE - bone marrow suppresion -> anemia, agranulocytosis, thrombocytopenia
Mental status change + nystagmus evoked by lateral gaze + bilateral weakness of lateral rectus muscles + memory impairment
Wernicke-KorsakoffT
Thiamine deficiency
Lesion of the mamillary bodies
Pt has lost sensation over 5th digit. Defect in which movement?
Wrist adduction (wrist flexion) ulnar n.
Following a seize a pt has intermittent headaches, memory loss, and vision changes. Mass in the right temporal lobe. What is the visual defect?
Upper left corner of vision bilaterally
Left homonymous superior quadrantanopia (pie in the sky)
NOTE this is contralateral vision loss
Damage to the Meyer’s loop
Pt is started on an anticonvulsant that blocks voltage-gated sodium channels. What is its effect?
Without an infux of Ca2+ following an AP the vesicles containing NT’s will be unable to fuse and release their cargo into the synaptic cleft
Pt on a medication for hearing voices develops a prolactinoma. This is due to interruption of which pathway?
Tuberoinfundibular pathway
Dopamine pathway that inhibits prolactin secretion
Rabies binds to which receptors?
Nicotinic ACh receptors
Rhabdoviridae, ssRNA, bullet shaped capsule
Best test for impaired attention and concentration in a pt?
Reciting months of the year backwards
Counting down from 100 in invtervals of 3 or 7
Spelling world backwards
